"Who's there?" cried Paula, her voice trembling slightly.
A noise suddenly echoed from above, causing everyone to stop in their tracks. They looked up, their hearts pounding, and saw a shadow move at the edge of the staircase.
¡AAAHHH!!
In the hallway on the second floor, they found a door ajar leading to a dark room. Carlos' flashlight illuminated the interior, revealing a dust-covered painting on the wall. As they approached to examine it, a current of icy air enveloped them, and the painting seemed to come to life for an instant, revealing distorted and terrifying figures.
A scream of terror escaped Paula's lips, and everyone backed out of the room, their breath coming in gasps. Charles' heart pounded, and he looked at his friends with uneasy eyes."I think this was a bad idea," he muttered, his voice full of doubt.
As the group retreated through the corridors, the mansion seemed to whisper dark secrets to them, and the mystery that enveloped them deepened. The adventure had barely begun, and already they had begun to unearth the abandoned mansion's sinister past.I hope this example has given you an idea of how a first chapter of a horror story might begin - if you need more help or want to continue the story, don't hesitate to ask!